European Patent Document PCT/EP90/00487 discloses a process for green fodder preparation in which mowed grass, for the acceleration of the drying process, is conveyed through a pressing nip by counter-rotating pressing elements and, for the production of a grass mat having substantially uniform density and cross section, the volume of grass supplied to the pressing nip is measured and the conveying speed of the pressing elements is controlled in dependence thereon. It has proved disadvantageous that, despite this control, the thickness of the grass mat distributed over the width of the grass mat is not of a uniform thickness. The use of rigid pressing elements (for example steel cylinders) has the consequence that the grass mat is partially not pressed. A loosening occurs in the grass mat where pressing is inadequate, and thus the drying process and also the subsequent picking-up process are impaired. In case of contaminants (e.g., due to stones) or too large a volume of grass, delays or failures of the preparation process occur.
From German patent document DE-OS 28 17 793 there is known a device for green fodder preparation, which has one pressing device for the acceleration of the drying process of mowed grass, consisting of two cylinders, the cylinders forming a pressing nip through which the grass is conveyed. The cylinders of the before mentioned pressing device are made elastically deformable. Further concrete information on the arrangement of the cylinders cannot be understood from this document. While the before mentioned document discloses a pressing device having two cylinders assigned to one another to form a nip through which the grass is, it does not disclose a pressing device consisting of a plurality of cylinders together with a belt around at least two cylinders.